Freezing (solid), Melting (liquid),

Evaporation (gas) Study

PresentationINCLUDING WATER STATE CHANGE GRAPHS

Lesson Vocabulary

1. Melting- solids gain heat and change into liquids

2. Freezing- liquids lose heat and change into solids

3. Evaporation- liquids gain heat and change into gases

4. Condensation- gases lose heat and change into liquids

5. Boiling- liquids gain heat and quickly change into gases

Changing State

How does an ice cube turn into a puddle of water?

-It melts

MELTING is the process by which a solid changes to a liquid.

To melt a solid, you must add (HEAT) energy to it.

How does a puddle of water change from a liquid to a gas?

-It can evaporate.

EVAPORATION is the process by which a liquid changes to a

gas.

What is happening when a liquid

changes into a solid?

FREEZING is the change of state

from a liquid to a solid.

*The particles move

slowly and get close

together. It causes liquid

to freeze.

Is this an example of melting, freezing,

or evaporating?

a) Melting

b) Freezing

c) Evaporating

Answers

In which state is the snow?

a) Melting

In which state is the puddle?

a) Freezing

In which state is the puddle on the

road?

d) Evaporating

In which state is the road?

b) Freezing

Part 2

Factors that

influence the rate

of Evaporation

Factor 1 - Temperature

The higher the temperature the faster the rate of evaporation.

Heat is added.

Which puddle will evaporate

faster?

A B

Factor 2 - Wind

The more wind or air circulation the faster the rate of evaporation.

Which puddle will evaporate faster?

A B

Factor 3 – Exposed Surface AreaThe larger the exposed surface area the faster the evaporation rate.

The water will evaporate more quickly from the beaker on the right with the wider opening.

3 inches1 inch

If each beaker contains 8 ounces of

water, which beaker will evaporate

the quickest?

Part 3

Factors that influence the rate

of Melting or Freezing

Factor 1 - Temperature

Remember the freezing/melting point of water is 0°C or 32°F.

The higher the temperature the faster water will melt. Heat is removed.?????

The lower the temperature the faster water will freeze. Heat is removed.

Factor 2 - Size and Shape

If you have two equal masses of ice – one in a solid block and the other in

smaller pieces - the smaller pieces will melt faster.

Factor 2 - Size and Shape (cont.)

Just like with evaporation, the more surface area exposed to heat the faster

water will melt. Likewise, the more surface area exposed to cold, the faster

water will freeze.

In which cup will the ice melt

quicker?A B

Factor 3 – Changing the

Composition

During the cold and icy winter, you have probably experienced salt on sidewalks and roads. It is used to melt the ice and snow and keep it from refreezing. The freezing point of water becomes lower as more particles are added until the point where the salt stops dissolving.

By adding salt to icy roads, you change the freezing/melting from 0°C to

point to -9°C.

Review – Four Factors that influence the

rate of Melting or Freezing

Factor 1 – Temperature (The hotter the air temperature the faster ice melts;

the colder the air temperature faster water freezes.)

Factor 2 - Size and Shape (Larger pieces of ice melt more slowly than an

equal mass of smaller pieces.)

Factor 3 – Changing the Composition (Mixing water with other compounds

such as salt will influence the melting/freezing point.)

Practice

Answer the following questions about factors that influence

the rate at which different types of material

freeze, melt, or evaporate.

Falling temperatures can affect

the water cycle by ______.

a) creating larger raindrops

b) changing precipitation from rain to snow

c) creating smaller raindrops

d) changing the path of water runoff

How does adding salt to water

affect the temperature?

a) The melting point increases to a higher temperature.

b) The freezing point increases to a higher temperature.

c) Salt does not affect the temperature of water.

d) The freezing point decreases to a lower temperature.

You are going camping for three days. You need to buy ice

that will keep your ice chest cool for the entire 3 day trip.

Which would be the best ice to buy?

a) one large

block of

ice

b) many small

cubes

c) crushed

ice

d) brightly

colored

cubes

At which of the following ground temperatures will the

puddle evaporate the fastest?

a) 50°C b) 15°C

c) 29°C d) 87°C

Your little sister forgot to turn off the water in the bathroom sink. The

water overflowed and soaked the carpet. You want to dry the carpet

out before your mother gets home. At which level should you turn on

the fan?

a) low b) high

c) medium d) The carpet would dry

out faster without a fan.

Students are investigating whether wind

affects the rate at which the sponge will dry.

Which experiment is best to use in answering their question?a) b)

c) d)

Each of the following containers hold exactly10

ounces of water. From which container will water

evaporate the fastest?

a) b)

c) d)

Which letter represents

evaporation?

At which temperature will the icicles melt the

quickest?

a) 50°C b) 15°C

c) 29°C d) 87°C

Water State Change Graphs

This will be on your FME quiz

Graphs show how water changes at different temperatures

What does the previous graph show

us?

Energy Added Graph

Which number location represents the location of melting?

1

2

3

4

Answer

1

Why location 1?

Reason: Location 1 is just above the “solid” line. The temperature is above

freezing (0 degress Celsius). This is when melting will begin.

What does the previous graph show

us?

Energy Removed

Which number represents the freezing point?

1

2

3

4

Answer

4

Why? This is when freezing begins. 0 degrees Celsius

Energy is being removed